asc book says:
"the principal disadvantage is the actual size of the 1.85 format on the negative. Because of the smaller area, 1.85 is noticeably grainier than anamorphic 2.40. is is not as noticeable in the original negative stage and projecting in small screening rooms, but becomes more pronounced when projected in large theaters."
"the most salient advantage is the much larger negative area. A 55% increase in negative area over 1.85, results in finer grain, better opticals, and an increase in apparent sharpness (I say apparent, because while a similar image photographed in 1.85 may be sharper, the increase in grain and greater magni cation actually make it appear less sharp). the difference becomes most apparent going through the dupe negatives."
"Many people believe it is an advantage to shoot 1.85 because spherical lenses are sharper than anamorphic 2.40’s lenses. is is a misconception. It is true that spherical lenses are o en sharper than anamorphic; however, the much greater negative area used with anamorphic more than makes up for the subtle di erence in resolution from spherical lenses. Properly executed camera tests comparing the two formats always reach this conclusion."